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Like an HTTP request, an HTTP response may include additional headers to modify or augment the response it provides. A full list of available headers is defined in §6.2 of the specification. The most commonly-used headers are: Server, which functions like a User-Agent request header for the serv...

A common problem is having a collection of items that all need to meet a certain criteria. In the example below we have collected two items for a diet plan and we want to check that the diet doesn't contain any unhealthy food. // First we create a collection $diet = collect([ ['name' => ...

You will often find yourself with a collection of data where you are only interested in parts of the data. In the example below we got a list of participants at an event and we want to provide a the tour guide with a simple list of names. // First we collect the participants $participants = colle...

A web worker is a simple way to run scripts in background threads as the worker thread can perform tasks (including I/O tasks using xmlHttpRequest) without interfering with the user interface. Once created, a worker can send messages which can be different data types (except functions) to the JavaSc...

In Java, parent and child class both can have static methods with the same name. But in such cases implementation of static method in child is hiding parent class' implementation, it's not method overriding. For example: class StaticMethodTest { // static method and inheritance public stati...

This is the easiest syntax to define a function: square(n) = n * n To call a function, use round brackets (without spaces in between): julia> square(10) 100 Functions are objects in Julia, and we can show them in the REPL as with any other objects: julia> square square (generic func...

A long-form syntax is available for defining multi-line functions. This can be useful when we use imperative structures such as loops. The expression in tail position is returned. For instance, the below function uses a for loop to compute the factorial of some integer n: function myfactorial(n) ...

Deferred function calls serve a similar purpose to things like finally blocks in languages like Java: they ensure that some function will be executed when the outer function returns, regardless of if an error occurred or which return statement was hit in cases with multiple returns. This is useful f...

pacman is a simple package manager for R. pacman allows a user to compactly load all desired packages, installing any which are missing (and their dependencies), with a single command, p_load. pacman does not require the user to type quotation marks around a package name. Basic usage is as follows:...

C++11 It's possible to write a generic function (for example min) which accepts various numerical types and arbitrary argument count by template meta-programming. This function declares a min for two arguments and recursively for more. template <typename T1, typename T2> auto min(const T1 &...

std::function can cause significant overhead. Because std::function has [value semantics][1], it must copy or move the given callable into itself. But since it can take callables of an arbitrary type, it will frequently have to allocate memory dynamically to do this. Some function implementations h...

static void testNumericPromotion() { char char1 = 1, char2 = 2; short short1 = 1, short2 = 2; int int1 = 1, int2 = 2; float float1 = 1.0f, float2 = 2.0f; // char1 = char1 + char2; // Error: Cannot convert from int to char; // short1 = short1 + short2; // Err...

Surround with Surrounds a code block with an if, for, <editor-fold ...> and more. Windows / Linux: Ctrl + Alt + T OS X / macOS: Cmd + Option + T

PowerShell remoting must first be enabled on the server to which you wish to remotely connect. Enable-PSRemoting -Force This command does the following: Runs the Set-WSManQuickConfig cmdlet, which performs the following tasks: Starts the WinRM service. Sets the startup type on the WinRM ser...

Using credentials from your local computer: Enter-PSSession 192.168.1.1 Prompting for credentials on the remote computer Enter-PSSession 192.168.1.1 -Credential $(Get-Credential)

static void Main(string[] args) { string url = "www.stackoverflow.com"; var pingTask = PingUrlAsync(url); Console.WriteLine($"Waiting for response from {url}"); Task.WaitAll(pingTask); Console.WriteLine(pingTask.Re...

java.util.Date to java.sql.Date conversion is usually necessary when a Date object needs to be written in a database. java.sql.Date is a wrapper around millisecond value and is used by JDBC to identify an SQL DATE type In the below example, we use the java.util.Date() constructor, that creates a D...

This code compiles: Integer arg = null; int x = arg; But it will crash at runtime with a java.lang.NullPointerException on the second line. The problem is that a primitive int cannot have a null value. This is a minimalistic example, but in practice it often manifests in more sophisticated f...

Sometimes a RecyclerView will need to use several types of Views to be displayed in the list shown in the UI, and each View needs a different layout xml to be inflated. For this issue, you may use different ViewHolders in single Adapter, by using a special method in RecyclerView - getItemViewType(i...

Cons-cells, structures, vectors, lists and such can be matched with constructor patterns. (loop for i from 1 to 30 do (format t "~5<~a~;~>" (match (cons (mod i 3) (mod i 5)) ((cons 0 0) "Fizzbuzz")...